Re: [RFC, PATCH 4/4] elf_core_dump(): Add extended numbering support

[Daisuke HATAYAMA <d.hatayama@jp.fujitsu.com>]

I agree with two of three cleanup ideas, but the last.

> > @@ -2079,11 +2139,19 @@ static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file, un
> >        if (!elf_core_write_extra_data(file, &size, limit))
> >                goto end_coredump;
> >
> > +       if (e_phnum == PN_XNUM) {
> > +               size += sizeof(*shdr4extnum);
> > +               if (size > limit
> > +                   || !dump_write(file, shdr4extnum, sizeof(*shdr4extnum)))
> > +                       goto end_coredump;
> > +       }
> > +
> >  end_coredump:

There are two reasons I wrote like this.

First, the code like

if (size > limit || !dump_write(file, obj, sizeof(*obj)))
   goto end_coredump;

is used as the common idiom in thourghout elf_core_dump().  Not
writing goto only at the last use seems unnatural for me.

Second, there is a possibility that new writing operation for section
header table will be added. If the goto is removed now, the patch
writer must rewrite it again.

Thanks for your comments.